Setup CouchDB 2.0 Cluster

Question

I am trying to setup a CouchDB cluster with some Raspberry Pi for a edge computing project. But all I did until now wasn't successful. I don't get a cluster working correctly.

This is what I did: I followed the setup guide from http://docs.couchdb.org/en/2.0.0/install/unix.html#

in combination with: https://medium.com/linagora-engineering/setting-up-a-couchdb-2-cluster-on-centos-7-8cbf32ae619f#.eopseqi4h

1. Installing the dependencies - worked without error
2. ./configure - worked without error

3. make release - worked without error

4. Following the guide: Add couchdb user:

   adduser --system --no-create-home --shell /bin/bash --group --gecos   
   "CouchDB Administrator" couchdb
   

   worked without error

5. mv rel/couchdb /usr/local/ - worked without error

6. chown -R couchdb:couchdb /usr/local/couchdb - didn't work in first place - no usergroup couchdb - added usergroup

7. changed node-name in /usr/local/couchdb/etc/vm.args: -name n1.couch.local added -kernel inet_dist_listen_min 9100and -kernel inet_dist_listen_max 9200 - didn't work - changed back to couchdb@localhost

8. staring db

   su - couchdb
   cd /usr/local/couchdb
   ./bin/couchdb
   

   -didn't work for me in first place, su pw - Authentication failed - switched user by sudo su and su - couchdb

9. db starts - runs, but throws error (ignored error for now, because db is running):

   [error] 2017-02-17T12:34:26.672758Z couchdb@localhost emulator ------    
   -- Error in process <0.354.0> on node 'couchdb@localhost' with exit 
   value: {database_does_not_exist,
   [{mem3_shards,load_shards_from_db,"_users",
   [{file,"src/mem3_shards.erl"},{line,327}]},
   {mem3_shards,load_shards_from_disk,1,[{file,"src/mem3_shards.erl"},
   {line,315}]},{mem3_shards,load_shards_from_disk... 
   [notice] 2017-02-17T12:34:26.672918Z couchdb@localhost <0.353.0> ----
   ---- chttpd_auth_cache changes listener died database_does_not_exist 
   at mem3_shards:load_shards_from_db/6(line:327) <= 
   mem3_shards:load_shards_from_disk/1(line:315) <= 
   mem3_shards:load_shards_from_disk/2(line:331) <=  
   mem3_shards:for_docid/3(line:87) <= fabric_doc_open:go/3(line:38) <= 
   chttpd_auth_cache:ensure_auth_ddoc_exists/2(line:187) <= 
   chttpd_auth_cache:listen_for_changes/1(line:134)
   

10. prepared two Raspberry Pi (2 CouchDB nodes) for cluster mode:

    curl -X PUT http://127.0.0.1:5984/_node/couchdb@localhost/
    _config/admins/admin -d '"conmonmrp"'` 
    

    • answer:

      "-pbkdf2-9ec43ace4195ee45a37773c9dfc2aba9380468cb, cddfb98dd1b2416dea2b53dc9fe9a31b,10"

    and

    `curl -X PUT http://127.0.0.1:5984/_node/couchdb@localhost/
    _config/chttpd/bind_address -d '"0.0.0.0"'` 
    

    • answer: "0.0.0.0"

    seems like commands have been accepted

11. Went on localhost:5984/_utils/ and tried to setup cluster - entered credentials (did not change IP and port) and added another node by IP (network IP, i.e. 10.228.101.210), created cluster to finish setup - fauxton accepted that without an error.

12. trying to get all nodes in the cluster by localhost:5984/_membership/ results in:

    {"all_nodes":["couchdb@localhost"],"cluster_nodes":     
    ["couchdb@10.228.101.210","couchdb@localhost"]}`
    

13. trying to add a database on one node and see it on another one doesn't work

I'am really new to that CouchDB thing at all, but I need to get that cluster running. I hope, my discription helps to find the problem. Altogether I got the feeling, that I am missing or missunderstandig an important point on that.

Best regards from Hamburg, DE

Answer 1

After having some trouble with setting up the cluster, a friend found the problem. It is necessary to change the name of the node in the /couchdb/etc/vm.args file. As I read in another post it is illegal to name it @localhost. I changed that to the IP-address of the device.

After that, everything works fine for me now.

Answer 2

Remember also, when setting up a cluster and finding issues when adding or restarting, etc... Make sure your "cookie" doesn't have spaces.